Area Forecast Discussion
Issued by NWS Cheyenne, WY

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FXUS65 KCYS 160010

Area Forecast Discussion
National Weather Service Cheyenne WY
610 PM MDT Sat Jul 15 2017

.SHORT TERM...(This evening through Monday night)

Issued at 609 PM MDT Sat Jul 15 2017

Tonight...Deeper moisture continues to exist over Colorado as
evidenced by satellite and radar imagery. However, visible satellite
imagery suggesting some cumulus buildups over our northern and
western counties, and thus have added low POPS through this evening
for these areas. Otherwise, expect isolated showers and
thunderstorms to dissipate by late evening with loss of daytime

Sunday...Relatively dry air continues aloft, limiting thunderstorm
development. However, there should be enough mid level moisture to
spark isolated afternoon showers and thunderstorms over our far
western counties of Carbon and Converse and over our Snowy and
Sierra Madre Ranges. Temperatures similar to those of today based on
700 mb temperatures.

Sunday night/Monday...Thunderstorms expected again to be diurnally
driven and should end in the evening with clearing skies thereafter.
Slow warming trend continues per 700 mb temperature trends. Models
indicating a slight increase in low and mid level moisture, which
will help spark isolated to scattered afternoon and evening showers
and thunderstorms, most numerous over the mountains.

Monday night...Isolated to scattered evening showers and
thunderstorms expected, most numerous over western Nebraska in the
vicinity of a low level convergence boundary. Dry after midnight as
the showers and storms will be diurnally driven.

.LONG TERM...(Tuesday through Saturday)
Issued at 609 PM MDT Sat Jul 15 2017

See an increase in convection from Tuesday on as GFS TPWs increase
to near an inch across much of the CWFA by Wednesday. This is due
to the upper ridge moving back to the east, allowing extra
monsoonal moisture to move into the area from the southwest.

Perhaps the best day for convection is Thursday. GFS showing an
upper shortwave interacting with the monsoonal moisture. ECMWF
shows this as well, but QPF confined further south across
Colorado. Will be watching this feature as we get closer to the


.AVIATION...(For the 00Z TAFS through 00Z Sunday afternoon)
Issued at 609 PM MDT Sat Jul 15 2017

Still expect mostly dry conditions to prevail, but a weak shower
is possible through sunset over the eastern terminals along a weak
cold front moving in from the northeast. Gusty easterly winds
will continue through sunset as well, then will be generally
light overnight. Should see breezy south to southeast winds return
along and east of the Laramie Range once again Sunday afternoon.


Issued at 609 PM MDT Sat Jul 15 2017

Minimal concerns as afternoon humidities will remain near or
slightly above critical thresholds, with limited wind.




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